I recently brought my 1993 Honda del sol into the shop with a blown motor and had a new one put in. I got the car back and noticed the engine looked a slight different than my old D15B7. I took a closer look and noticed it was a ZC engine. Under where it says ZC it says 591Z609 or 5912609 (sorry wrote it down on my hand and can't tell if i wrote was a 2 or a Z). anyways. i was wondering if i gained any horsepower from the accidental engine swap. I am also concerned about legal issues. In the state of California it is illegal to have an engine in yoru car older than your car. We bought the engine from a honda engine import company and i don't know what year the engine is. ON the paperwork it says we ordered the D15B7 but we didn't get one. or am i just dumb and the ZC and D15 are the same engine. i do'nt think so but i could be wrong.